Pattern control means for shotguns



June 27, 1950 G, B, CRANDALL 2,512,850

PATTERN CONTROL MEANS FOR SHOTGUNS Filed sept. 5, 1947 Y INVENro@..CQANDLL Patented June 27, 1956 p 2,512,850. i PATTERN CONTROL MEAN-sFoitsrl*Po'rdn1\1sfv Gladstone Blakeorandan. vvqqdstoek. Ontario,Canada- Application September 5, 1947; Serialil Noz' '77254135 2Glaims.V (Cl. 42h-i791) .invention relates.to.shot pattern controlmeans'for-shotguns.

Knownpattern control devices for shotguns are obtainable: in @varioussizes as attachments which maybathreaded onto the end of thebarrel ofthe rearm to control the -distribution of the shot andwimprovewthe`target pattern. A .full choke, which is anattachmen-t having a finalrestricted bore,:will vcause between.75% and 80% ofthe shot to bedistributed. within a 30.3-inch. circle at a distance of 40 to 50 yards.A modied. choke ,will give =a 65% distribution and an improved cylinder,whichractually, has .nolrestrictionat all .but is merelya continuationofthe true diameter of the boreof the; gun, .will give a 50% pattern. Aserious.:disadvantage, however, attends the use :of chokesqinthat .asharp muzzle blast is experi-y enced vwhich is annoying not only. to theiirer but to'fellow sportsmenstandingnearby.

Compensatorshave been. provided. which have ventggholesallowing some ofthe. gases to escape before thefshot leaves theY mouth .of thechoke,but,

inleveryjnstance., such vent holes` are for the purpose Q f reducingfrecoil or kick and serve actually to aggravatethe annoyance to aby-stander due largelyto the directing of the gases to either sideaof.thefmuZZleQ Conventional compensators and-...chokesiareconsidered asvery noisy .attache ments and although used widely in order ,to ob.-tain an improvedpattern with less. recoil, they are. `.used ispiteiofthe, disadvantage of .discom-V fort not only ,toxthe iirerof theweaponbutto by-standers;

It is the .particular object of the present inventionzto .provideimproved. attachments for` shotgunscwhich includea vent piece in whichthe vents yarein .theform .of aY plurality. of axial slots of lconsiderable ,length :which are adapted. to allow escape of the. gasesand dissipation of `the same to reducemuzzle blast.v

Anotheraobject-of the invention is to provide attachments. asrbeforeincluding a vent piece in which the slots due-.to their ksubstantiallength, allow the. gases to proceed in a forward direction due to theirmomentum so that blast noise will notfbe: directed either'b'ackvtowardsthe frer or tofeitherside. in the direction of by-standers.

A further-object: of ther invention is to .provide attachmentsrforShotguns including a vent piece in :which-the'. surfaces of the boremate Withthe bore'surfaces of thegun barrel to conne-the shot in thedesired manner` and yet allow escape of gases: through theventswhich areof such awidth that thezshot will -`notlpass therethrough.

A still Vfurther. object of the invention is to pro.

vide a lightbweightpattern control ydevice for-the muzzleof av shotgunbarrel which'is formed-'substanti'all-y of a simpletubelhaving.longitudinalslcts .in parallelly spaced apart radial relation-extendinglongitudinally over a substantial-portion thereof to vallow the escapeof .propellent'gases-in a forward direction*under` their ownv momentumwithout undu-lyrinipeding'the latter in their for- Ward-movement. I

. A still further objectof 4the-invention is to'pro-I videattachmentsfor Shotguns comprising a vent pieceand a pattern tubedesigned to'be attached thereto forr Skeet shooting` .in particular in`which the entry dimensionsof the bore of the skeettube arein excess ofthe exit dimensions of-thefbore of the. .vent piece-and.the-barreloflthecguntto which the vent piece is attached;

A still further .object of the invention -is to =pro vide Aa vent pieceand Apattern tubes. therefore which have'an entry bore lof thesameldiameter as the bore. of the gun to .which thevent pieeeaisattachedythe. said `pattern tubes having constricted bores .to-lsubstantially. conform with:v chokes of various 4characteristics .andsizes.

With these and# other objectsvin view, the vin-H vention generallycomprises a light :Weight vpattern control .device formed from. a 'thin.Wall tubular body having a continuous and uniform .innen-bore diametervequal to the diameter of the muzzle-bore of the'shotgun barrelvto.which the device is designedtmbeattached. '.Vent meansin the form oflongitudinally extending slots are provided in the` tubular body of suchwidth that the smallest shot cannotpass therethrough exteriorly of thebody. These .vents are of such length that shot or propellentgasesareallowed to exhaust underv their. own momentum vforwardlywithout'inate-I rially kvimpeding'their forward direction :of move#ment..

An alternative includes in the combination :a pattern tube which may beintegrally formed with fthe .tubular body. and which determines initialshot distributiomvIn this connection the entry bore of the pattern tubemust` be .of a di-i ameter equal` to .thesdiameter of the. borezoi Athe*tubularbody.

Another alternativeconcerns. the provision of an alternative form oipattern tube particularly adapted for Skeet shooting and having apattern controlling bore the diameter of which is greater than thediameter of thebore of the tubular body.y This modication includesenlarged vents insthe pattern tube designed to substantially completevthe; exhaust of gases and being. ofa length less.

than the distancebetweenvthe entryof itsbore and the point of engagementof shot with the walls thereof.

Other objects of the invention will be apparent from a study of thefollowing specification taken in conjunction with the accompanyingdrawings.

In the drawings,

Figure 1 is a sectional view of pattern control means according to myinvention showing a Vent piece mounted on the muzzle end of aconventional shotgun barrel and in turn mounting a pattern tube in theform of a choke of improved type.

Figure 2 is an illustrative diagrammatic view of walls of the gun barreland pattern control means of Figure 1 indicating gases escaping from thevents of the vent piece and further indicating the effect of the borerestriction of the pattern tube on shot moving through the bores andshown at two locations therein.

Figure 3 is a sectional view of a modified form f of pattern controlmeans showing a vent piece as in Figure 1 by mounting a pattern tube ofdistinctive design, which I recommend for skeet shooting and the likebeing therefore known as a skeet tube and having vents of particularcharacteristics.

Figure 4 is a diagrammatic illustrative view of the walls of the boresof the pattern control means and gun barrel of Figure 3 showing gasesescaping from the vents of the vent piece and the skeet tube, andshowing the effect of the enlarged bore of the skeet tube on thedistribution of shot by illustrating two positions of shot in the bores.

YFigure 5 is a' sectional view of pattern control means equivalen-t tothat disclosed in Figure 1 by illustrating that the two components, thatis to say, thevent piece and the pattern tube, may be formed in onepiece if desired.

Referring tothe drawings and particularly to Figure 1, pattern controlmeans according to my invention are shown, and comprise generally a vent,piece IU and a pattern tube II. The vent piece I0 is threadedinternally for mating with threads I2 on the muzzle end I3 of aconventional shotgun barrel I4. The other end of the'vent piece I0 isdesigned for mating with threads I5 on the entry end I6 of the patterntube II.

The vent piece in the body portion I1 between its ends has apluralitytof vents I8 (preferably 12 in number) which extend over amajor portion of the muzzle I3 and entry end I6 of the pattern tube I I.Vents I8 according to my invention, must be'of a width which is lessthan the smallest diameter of shot for which it is to be used.Therefore, as a ball of shot passes through the bore I9 of the body I1,each ball of shot will not tend to pass through the slots I8, but thelatter serveto provide a means of exhausting the gases before the shotenters into the pattern tube II. cordance with the invention, the wallsof the body I1 are comparatively thin, that is to say, their thicknessis comparable with the thickness of the walls of the muzzle end I3 ofthe shotgun barrel I4.r It will be noted that the bore I9 of the body I1is continuous and uniform in diameter and equal to the diameter of thebore of the muzzle end I3 of the shotgun barrel I4 as illustrated in allforms, that is to say, the forms of Figure 1, Figure 3,-and Figure 5.

`I prefer tosupply at least three pattern tubes to the sportsman whichwould substantially correspond to conventional chokes. An improvement,however, will be evident in that the entry end I6 of the bore 20 of thepatterntube` II has its surfaces meeting or in line with the surfacesarbore' I9 of the vent piece I0` The bore 28 is lio restricted towardsthe muzzle end 2| in accordance with the amount of choking required,that is, full choke, medium choke, or the improved cylinder type of borewhich has no restriction whatever.

Referring to Figure 2, the effect of my pattern control means willreadily be appreciated. The walls of the bores of the barrel I4, ventpiece I0 and pattern tube I I are `represented by the lines 22, thechain lines 23 indicating that openings or vents I8 are located in thisregion which is vbounded by the right angular lines 24 and 25. uTerminal lines 26 indicate the muzzle end 2| of the pattern tube I I.The irregular hatched areas 21 and 21a illustrate the two positions of acharge of shot as it proceeds through the bores 21 indicating that theshot is relatively undisturbed by the exhaust of gases (indicated bylines 28) forwardly through the vents I8. It is important to note thatdue to the considerable length of the vents I8 that the gases areallowed to proceed substantially in the direction of their momentum,that is, forwardly. The shot will proceed through into the pattern tubeand be restricted diametrically to distribute the charge in a morelongitudinal manner as at 21a, so that it is Well packed andconcentrated before it leaves the muzzle terminal points 26. The amountof restriction in the bore of the pattern tube I I will, of course,determine the nal distribution in the pattern of shot at a target. i Inthe sport of skeet shooting in particular, muzzle blast fromconventional types of chokes is excessive and usually annoying tobystanders. I, therefore, provide a particular design of pattern tube 29shown in Figure 3 which may be mounted on the vent piece I0. Thisspecific embodiment of pattern tube hereinbefore referred to as a Skeettube has an enlarged cylindrical bore 30 of a dimensi-on in excess ofthe diameter of the bore I9 of the vent piece I0. Enlarged ventsf3I(preferably six in number) are provided to allow a iinal exhaust ofgases before the charge (not shown) leaves the muzzle end 32 of theskeet tube 29. The

skeet tube has an entry end 33 having a borev 34 designed for matingwith the bore I9 of the vent piece I0. This entry end also carriesthreads 35 for mating fixture with the Vent piece substanmeanslcorresponding to the elements shownin' Figure 1. vIn this case, however,it will be observed .that lines 36 represent the enlarged bore 30 of theskeettube 29 and then 'chain lines31 represent vents13I and terminallines .38 the muzzle end 32. Here the shot. 21Y proceedstoward the skeettube k29 confined as before-but upon reaching the enlarged bore ofthis'latt'er tube'it spreads out as indicated by lines 39 and engagesVthe walls of the bore 36 at a point more clearly indicatedby numeral 40in Figure 3, the ball of the shot substantially following the path Y.Gases which have not been exhausted through the vents I8 of vvent piecelI0 willbe exhausted through vents 3I as indicatedby lines 4I, beingmoved forwardly as indicated by the I0. passed the vents 3l, showing itsspreading to meet the walls 36 of the bore of the skeet tube and beingsubstantially undisturbed insofar as the distribution of shot in thecharge is concerned. As a result, therefore, the shot 2lb will beexpelled from the muzzle 32 of the skeet tube 29v substantially by itsown momentum, maximum control on the distribution of a shot beingthereby accomplished by the muzzle end surfaces of the bore 30. Afurther advantage is that muzzle blast is substantially obviated asregards bystanders since the gases proceed forwardly as described, thosegases which do pass out of the vents of the Skeet tube being ofrelatively small volume as compared with the volume of gases passing outthe vents IS. Vents 3l are preferably very large and may be of a widthgreatly in excess of the balls of shot proceeding through the bore 30 inorder to allow as quick an exhaustion of the remaining gases as possibleso that the distribution in the charge 2lb will remain substantially ineffect by these gases.

Figure 5 is included merely to illustrate that the pattern control meansof my invention may be incorporated in one unit if desired, in whichcase the device is comprised of a body 42 having a bore 43 of the samediameter as the bore of the gun barrel i4. A plurality of vents 44 areprovided which substantially correspond to vents i8 of Figure l havingthe same characteristics. The muzzle end @5 of this device is formedintegrally with the body 42 and has a restricted bore 16 substantiallyas indicated and corresponding to the restriction necessary for variouschoking eiects, one end of this combined Vent piece and pattern tube isdesigned for mating with threads I2 on the muzzle end i3 of barrel l. Itwill be appreciated, of course, that the skeet tube and vent piece ofFigure 3 may be made in one piece in a similar manner. An example of anobvious additive feature is illustrated in Figure 1 Where a sightingbead 41 mounted in a sighting mount 48 is fastened into the body l1 ofthe vent piece I0 by the lug 49. Experiment with the pattern controlmeans of Figure 1, in particular, has shown an improvement over thepattern distribution obtainable with standard chokes of a further tenper cent concentration with the different pattern tubes.

-The specific design of Skeet tube shown has proved capable of placingsubstantially ninety per cent of the shot within a thirty-inch circle attwenty-five yards as compared with roughly sixty per cent within thecircle under similar conditions with former types of chokes normallyused in skeet shooting. A particular advantage derives from confiningthe bores of the attachments described to an entry dimension whichcorresponds to the dimension of the bore of the gun barrel I4 since theshot will be conlned as it travels through these bores and the waddingor packing will not wobble to disturb the distribution of the shot onthe iinal target. Many obvious modications will be apparent to gunmakers apart from the specic embodiments described and, therefore, it isintended that the present disclosure should not be construed as limitingin any way other than that indicated by the scope of the followingclaims.

What I claim as my invention is:

1. A light weight shot pattern control device for the muzzle of ashotgun barrel, comprising, a vent piece in the form of a tubular bodyhaving a continuous and uniform bore of a diameter said tubular bodyhaving walls substantially equal in thickness to the thickness of thewalls of the shotgun barrel at the muzzle end, and pattern controllingmeans comprising a pattern tube extending from the other end of saidbody designed to determine distribution of shot by controlling thelatter as they pass therethrough substantially under the influence oftheir momentum alone, said pattern tube having a pattern controllingbore of a diameter greater than the diameter of the bore oi said tubularbody and a plurality of radially positioned parallelly spaced apartlongitudinally extending slots forming Vent means in said pattern tube.

Csi

2. A light Weight shot pattern control device for the muzzle of ashotgun barrel, comprising, a vent piece in the form of a tubular bodyhaving a continuous and uniform bore of a diameter equal to the diameterof a muzzle bore of the shotgun barrel, means for fastening one end ofsaid tubular body to the muzzle of the shotgun barrel and providingalignment of the bore of said body with the bore of the muzzle of theshotgun barrel, said body having a plurality of radially positionedparallelly spaced apart longitudinally extending slots forming ventmeans for allowing the exhaust of propellent gases from the bore thereofexteriorly and forwardly of said body, said tubular body having wallssubstantially equal in thickness to the thickness of the walls of theshotgun barrel at the muzzle end, pattern controlling means comprising apattern tube extending from the other end of said body designed todetermine distribution of shot by .controlling the latter as they passtherethrough substantially under the influence of their momentum alone,said pattern tube having a pattern controlling bore of a diametergreater than the diameter of the bore of said tubular body, and aplurality of radially positioned parallelly spaced apart longitudinallyextending slots forming vent means in said pattern tube, the vent slotsof the latter being wider than the diameter of shot propelled throughsaid pattern tube and extending in longitudinal dimension a distanceless than the distance from the entry end of said pattern tube to thepoint of engagement of shot with the surfaces of the bore of saidpattern tube.

GLADSTONE BLAKE CRANDALL.

REFERENCES CTED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 85,949 McKenzie Jan. 19, 1869618,901 Peterson Feb. '7, 1899 1,598,360 Pavek Aug. 31, 1926 2,098,617Cutts Nov. 9, 1937 2,115,028 Logan Apr. 26, 1938 2,428,232 Limon Sept.30, 1947 2,442,899 McAllister June 8, 1948

